Cylinder mold for paper making machine



Aug. 17, 1965 L. M. STUEBE ETAL CYLINDER MOLD FOR PAPER MAKING MACHINE 5 Sheets-Sheet l Filed Jan. ll, 1962 sau ATT RNEYS' Aug. 17, 1965 L. M. sTUEBE ETAL CYLINDER MOLD FOR PAPER MAKING MACHINE 5 Sheets-Sheet 2 Filed Jan. ll, 1962 Aug. 17, 1965 L.. M. STUEBE ETAL CYLINDER MOLD FOR PAPER MAKING MACHINE 5 Sheets-Sheet 3 Filed Jan. ll, 1962 United States Patent O 3,201,309 CYLENBER Mll@ FR PAPER MAKEN@ MACLLHNE Louis M. Stuebe and .lose-ph D. Parker, Beloit, Wis.,

assignors to Beloit Corporation, a corporation of Wisconsin Filed lan. 1l, 1962, Ser. No. 165,696 9 Claims. (Cl. 162-3557) The present invention relates broadly to the drainage of liquid from the interior of rotating filter units such as the cylinder molds of paper making machines, and is particularly concerned with the provision of pumping vanes in rotating cylinder molds effective to enhance liquid flow out of the ends of the mold interior along the entire width of the mold, thereby permitting the production of a level basis weight product.

Currently, in the art of counterflow vats, the cylinder mold is immersed in a pond of liquid containing suspended paper fibers therein. The pond is continuously supplied at arrate which will maintain the pond level against the mold at the desired elevation. A continuous flow of liquid takes place from the pond into the cylinder, which is of an open surface construction covered with a fine weave wire mesh. As the liquid flows into the cylinder, the fibers suspended therein are deposited upon the surface of the wire mesh to form a fibrous mat.

In this arrangement, the liquid or white Water within the mold flows outwardly through the opposite ends thereof. This creates a gradient from the center of the molds to the ends. Since, as is known, the drainage from the pond into the mold is related to the difference between the pond level and level in the mold, it is apparent that the amount of liquid flowing from the pond into the mold will vary from point to point across the width of the paper machine. This difference in rate of flow frequently causes a corresponding difference in the weight of the mat formed on the mold surface from point to point thereacross, that is, in the basis weight profile.

It is, therefore, an important aim of the present invention to provide new and improved cylinder mold apparatus featuring therein means for pumping the liquid from opposite ends of the mold interior to provide a uniform discharge level within the mold by overcoming the normal piezometric head gradient.

Another object of this invention lies in the provision of a cylinder mold of open-ended construction having hub means mounting thereon at predetermined locations radially extending and circumferentially spaced blade means for pumping fluid toward opposite ends of the mold, thereby providing a uniform fluid flow rate entirely along the length of the mold.

Still another object of the instant invention is to provide, in a machine having a rotating filter unit receiving filtrate in the interior thereof, vanes in the unit which are rotatable therewith and effective to `induce filtrate flow out of the unit.

A further object of this invention is to provide a cylinder mold machine having a rotatable forming cylinder receiving white water therein, the cylinder being equipped with vanes therein for inducing water flow toward both ends of the cylinder to maintain a uniform water level in the cylinder and thereby effect uniform paper formation across the width of the machine.

Other objects and advantages of the invention will become more apparent during the course of the following description, particularly when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals designate like parts throughout the same: p

FIGURE 1 is a fragmentary sectional view, with parts rice in elevation, taken through a cylinder mold and vat arrangement constructed in accordance with the principles of this invention;

FIGURE 2 is a partially broken and fragmentary elevational view of a mold cylinder according to this invention, with certain portions thereof being talcen in section;

FIGURE 3 is a fragmentary sectional view through another mold cylinder embodying the novel concepts of this invention;

FIGURE 4 is a fragmentary end elevational view of the cylinder of FIGURE 3, portions thereof being shown in section; and

FIGURES 5 and 6 are views illustrative of exemplary blade angles and angles of attack for the vanes in the embodiment of FIGURES 3 and 4.

One form of apparatus of a high order of effectiveness in overcoming the normal piezometric head gradient within a cylinder mold, and permitting the production of a fibrous sheet having a level basis weight, appears in FIG- URES l and 2. Prior however, to describing the embodiment of these two views, it is desired to note that the general structural organization shown is exemplary only and is illustrated in detail sufficient to clearly understand the instant concept of providing vanes in a rotatable forming cylinder for inducing Water flow to both ends thereof, in order to maintain a uniform water level in the cylinder and thereby effect uniform paper formation across the width of the cylinder mold machine. Obviously, the par ticular type vat employed may be varied, as for example, the vat may be of the counterow, unifiow or crossflow type.

As is shown in FIGURES l and 2, a cylinder mold machine generally designated by the numeral 10 comprises a main feed box 11 and an auxiliary feed box 12 located on each side of a stock pond 13 defined by a vat circle 14. A cylinder mold 15 is rotatably mounted in the stock pond 13 in spaced relation from the circle 14.

The cylinder 15 has a wire mesh peripheral face 16 supported upon a plurality of axially spaced annular rim portions 17 integral with circumferentially spaced vanes 18 which are integral with or otherwise suitably connected to sleeve means 19 carried upon hub means 20 supported by shaft means 21 journaled at opposite ends in bearing means 22a and 22b. Further details concerning the vanes 18 will be later set forth.

The ends of the cylinder are preferablysealed from the stock pond 13, and for this purpose the rim portions 17 on the endmost vanes 18 are provided with flanges 23 extending laterally from the ends of the cylinder. Vat end walls 24 are equipped with chime rings 25 having the same outer diameter as the flanges 23 on the endmost rim portions 16. The rings 25 are secured to the vat walls 24 in any suitable manner and extend inwardly therefrom, terminating but a short distance from the laterally extending flanges 23. Straps or bands 26 are placed around the rings 25 and the flanges 23, thereby sealing the ends of the cylinder from the stock pond 13. Since the straps 26 are only in frictional engagement with the rings and flanges, the cylinder may rotate relative tothe rings 24.

The end walls 24 of the vatextend considerably `above the stock level of the vat .and are provided near their tops with openings 2.7 to which a-re secured pipes or ducts 2S for communicating with the interior of the cylinder 15. The ducts 2S are connected through ducts 29 to ail` blowers (not shown), so that air is sucked from `the interior yof the cylinder, thereby aiding the fibrous web` formation on the wire mesh 16 of Ithe cylinder.

As appears in FIGUREZ, the fibrous stock in yaqueous suspension is supplied to the main feed box 11 throngh a feed pipe 39. The stock then passes through a perforated flow-evener board 31 and uows upwardly around U a horizontal baffle board 32 over a vertical baffle 33. The stock then flows downwardly under a vertical batflle 34 and up over Weir portion 35 of the circle 14 and into the stock pond 13 in the vat.

As shown in -FlGURE 2, openings 36 are provided in the end walls 2d of the vat structure adjacent the weir 35 for receiving trough members (not shown) opening into cylindrical pot-like members 33. Floats 39 are freely movable in the cylindrical members 38 so that the `stock level maintained in the vat pond 13 seeks its own level in the open troughs and cylindrical members 3S, thereby actuating the floats 39. These floats maybe connected by means of rods itl to lever arms il pivoted about an axis 42 on stands 43 secured to the vat Walls 24. A weight 44 is manually adjustable on the lever arm `41 to limit the action of the float 39 as the operation of the machine may require. As is now known, if the level of stock in the pon-d 13rises, the level of the stock in the cylindrical members 3S will also rise, thereby lifting the floats 39 and moving the rods -ft'ti upward to tip downward those portions of the lever arms lil beyond the pivots ft2. The ends of the lever arms 41 away from the floats and.l rods 4@ are secured to rods 45, which in turn control lthe operation of white water discharge valves lo (FIGURE l) in a manner to be later more fully described.

As stock flows into the pond 13, most of the fibers are deposited on `the screen surface ld of the cylinder 15 forming la fibrous web. However, foreign materials and the more dense brous particles collect at the bottom of the pond. A sump portion or catch basin 5d is provided at the bottom of the circle l.'- for collecting the foreign materials.

if desired, the dense fibers which find their way to near the bottom of the pond may be re-circulated, and an earlier proposed arrangement suitable for this purpose may include a slotted pipe S1 extending longitudinally across the bottom of the circle la, as is shown in FIGURE 1. The slotted pipe 5l is connected through pipelines 52 and 53 at each end thereof to a pipe 5d leading to the intake end of a motor driven centrifugal pump (not shown). Valves 57 and 5S are provided in the pipelines 52 and 53 for controlling the flow therethrough.

By means of a pipeline do the discharge end of the centrifugal pump is connected to the feed box 12, and in this manner the dense fibers at the bottom of the pond 13 are sucked through the slotted pipe 5l and are pumped into the feed box l2 Where they flow upwardly around the baes 61 .and 62 and over weir 63 of the circle 14. These dense fibers are thereby directed against the wire mesh lo of the cylinder 1.5 as the cylinder first enters into the stock pond 13. These dense fibers are thus initially deposited on the bare wire surface 16 and, as the cylinder rotates through the pond 13, the initially deposited fibers act as a filter for the finer fibers and thereby prevent the passage of the latter fibers through the Wire mesh into the interior 4of the cylinder.

As is shown in FIGURES l and 2, the end walls 24 of the apparatus are provided with vertically extending openings 65 communicating with vertical discharge boxes 65 which are open at their middle portions to communicate with horizontally extending boxes t?? which form supports for the bearing means 22a and 2lb for the cylinder 15. The boxes 67 `are provided aty one side with openings 63 communicating with weir boxes 69 in which the valves 46 are pivoted.

In this manner, White Water from the interior of the cylinder 15 flows through the openings 65 in the end walls 24 into the vertical boxes ed. The boxes 66 cornmunicate at one end with horizontal boxes e7 having a closed top and side, but communicating through an opening 6d, with weir boxes 69. The effective height of the Weir boxes 69 is varied by the valves 4d, which are raised and lowered by .the rods 4S actuated in turn by the lever 41. l

The valves 46 may be seen to have arcuate faces and are pivoted on the side Walls of the Weir boxes 69. The valves 46 thereby constitute adjustable slice bars, and aS they are lowered, the liquid level of the White water in the cylinder is also lowered. Since the valves do are controlled by the stock level in the pond 13, it is apparent Ithat a constant level of stock in the vat pond is maintained, since a rise in lthe level of the pond raises the floats 39 which lowers the valves le and thus :lowers the white water level in the cylinder. Since an increased differential head is thereby created, it is obvious that more white water will flow from the pond 13 into the cylinder and will thus tend to restore the original stock level in the pond. The valves id thereby maintain a constant level of stock in the vat by controlling the white Water discharge.

As was stated earlier, t-he instant invention is directed particularly `to the provision of vane means in a rotatable form-ing cylinder of a cylin-der mold machine, the vane means lbeing highly effective to induce water flow to both ends of the cylinder and maintaining a uniform water level in the cylinder to thereby effect uniform paper formation across the width of the machine. The structural details of the machine l@ which have been described, and with the exception of the vane means l, are accordingly illustrative only and provide a suitable environment OF the present invention. The cylinder mold machine need not be equipped with a recirculation system, and the vat utilized may be either of the counterow, crossflow or unilow type. As well, the provision of vane means is n-ot limited in usage to paper machines, and may be employed with any rotating `filter unit which receives filtrate in the interior thereof, since as will now be more fully understood, the vanes in such a rotating filter unit are effective to induce filtrate fiow out of the unit.

ln accordance with the novel aspects of this invention, flow of white water from the interior of the cylinder 15 through the openings 65 in the opposed end walls Z4 is induced by the vane means 18 so as to maintain a uniform water level in the cylinder 1S, thereby avoiding the formation of a non-uniform fibrous product. As was previously stated, the drainage from the pond f3 into the cylinder l5 is related to the difference between the pond level and the white water level in the cylinder. Accordingly, even though the white water level in the cylinder is under control of `the floats 3? and valves de, particular conditions may cause the amount of liquid flowing from the pond into the cylinder `to vary from point to point across the width of the paper making machine. This difference in rate of ilow causes a corresponding difference in the weight of the mat formed on the screen surface ld from point to point across the face of the cylinder. Generally speaking, the mat is heavier adjacent the ends by reason of faster drainage in these regions. This effect is of course somewhat exaggerated because the board is made up of multiple layers. Such uneven formation is particularly disadvantageous since it hampers converting operations by the resulting greater bulk and/ or weight at the edges, as compared to the center of the sheet or board.

In the arrangement of FIGURES l and 2, the pumping or fluid iiow inducing vanes )'18 provide the structural support for the forming surface f6, although asV will be noted in connection with FIGURES 3 and 4, the vanes may be structurally independent of the screen supporti means.

The vane means l in FIGURES 1 and 2 may be seen to be axially spaced along the length of the hub means and that two groups of vanes ld and 13b are provided, the vanes 18a effectively pumping to the left as viewed in FIGURE l and the vanes llb to the right in this same view. illustrating blade angles and angles of attack will be set forth in connection with FIGURES 3 and 4. f

The vanes a and le when viewed in end elevation are generally triangularly shaped, and each vane or blade is circumferentially offset from the next blade in a series.

n the illustrative arrangement of FIGURES l and 2, six vanes are shown in each axially spaced group of blades and are indicated by reference numerals 18C and 18d respectively, although of course this number may be varied. The vanes at their radial inward ends may be welded to the sleeve means 19 or can be equipped with stub shafts threadably received inthe sleeve means. As well, welding techniques may be employed to secure the rim portions 17 to the vane means 18 to provide the necessary support for the forming screen 16. In any event, white water inthe interior of the cylinder is urged or pumped in opposite axial directions from the center of the cylinder toward the opposite ends thereof at an essentially uniform ilow rate so that any possibility of uneven or non-uniform mat formation across the width of the machine is avoided.

` The novel ow inducing means of this invention may also be readily adapted to an existing cylinder mold machine, and this is illustrated in FIGURES 3 and 4, wherein like numerals from FIGURES l and 2, raised by an increment of 10), have been employed to designate likeparts. As appears in FIGURES 3 and 4, a cylinder mold machine 11) has on the hub portion 120 thereof sleeve means 119 equipped with radially extending and circumferentially spaced spoke or spider means 75 axially spaced along the hub means 120. The spider or spokes 7S at their radially outward ends are equipped with an annulusor rim 76 notched to receive a plurality of circumferentiallyspaced and axially extending rod members 77 which are in turn notchedto mount a spirally wound tape 7 8 seated on end in the notches thus provided and furnishing support for the screen surface 116. Of course, other cylinder structures can be utilized, and the rod and tape arrangement of FIGURES 3 and 4 can be employed in the embodiment of FIGURES l and 2. As well, in substitution for the tape means 7S a spirally wound wire can be used.

The rods 77 are received at opposite ends in suitable openings in rims 79 carried by the Sleeve means 119, and therim 79 cooperates with chime rings 125 to receive straps or bands 126 to seal the ends of the cylinder 115 from the stock pond.

` In the novel arrangement of FIGURES 3 and 4, there is provided in axially spaced relation to the groups of spoke means '75 vane means 80. The vanes Si) are suitably supported by the sleeve means 119 in the manner earlier discussed in connection with FIGURES l and 2, and the vanes Si) in the lefthand halt` of the cylinder 115 face as shown, While the vanes in the right half of the cylinder 115 face in the manner of the vanes 18h in FIG- URES l and 2. arrangement, the vanes 80 do not support the forming wire 116 and are of lesser radial length than the spoke means 75. While the number of spokes 75 on each spider orsleeve 119 may be varied, in the exemplary structure of FIGURES 3 and 4 six axisymmetric `spokes are provided. For convenience in viewing FIGURE 4, the spokes on a particular spider are identied by the legends '75a and the spokes on an adjacent spider, being displaced from the spokes 75a, are identied by the legends 7511. The arrangement of spokes illustrated thereby provides twelve openings 81 extending throughout the axial length of the mold cylinder, these openings being approximately triangular when viewed in end and providing uid flow paths for the discharge of the white water through the.

openings in the end walls 124 into the vertical boxes in the manner of FIGURES 1 and 2.

p As is of course appreciated, a dierent number of spokes and a variation in the angular displacement therebetween may he utilized in accordance with the instantv inventive concept. As appears in FIGURES `3 and 4, the vanes '80 are disposed in axial alignment with the openings 81 provided between the spokes 7S, and six vane In contrast` with the earlier described E members are utilized, although again this number may be varied.

Investigations have been conducted to determine the number of axially spaced groups of blades, or as otherwise stated the number of axial locations, as well as the number of blades per axial location, the area for each single blade, the blade angle of attack for each blade, and the axial distance for each group of blades from the vertical centerline or middle of the mold. To make these calculations, certain machine operating conditions may be assumed:

Wet end speed 450 fpm. Outside diameter of mold 60 inches. Wet end basis weight per mold 8.33 lbs./l0)0 ft?. Overall net drainage consistency 0.3%. Half-length of mold through which drainage occurs 117 inches. Cross-sectional area of water channel inside the mold 6 ft2. Depth of level below mold axis 6 inches.

It was further assumed that the axial flow inside the mold was unidirectional with a level surface and uniform drainage across the mold.

Under the condition that the individual blades mounted axisymmetrically about the mold axle (axle diameter: 20 inches) extend 15 inches radially from the axle, the following approximate expressions deine the blade variables:

N=num`ber of axial locations of blades, dimensionless. Izq-:total head drop from center to edge of mold, ft. n=number of blades per axial location, dimensionless. Av=single blade area-span, l, x chord, c, ft?. otr-:angle of attack, degrees. x=axial distance from middle of mold, inches. ,Bzblade angle, degrees (measured from plane .L mold axis). To determine the location of each of the N axial loca- The limits of these variables are as follows:

a=l to 15 N=1, 2, 3 11:2, 8, 4, 6, or 12 Av=-3 to 1.25 ft.2

For example, if the blade area, number of blades per axial location, and angle of attack are selected as .45 ft?, 4, and 8, then for a total head drop of 3 inches or .25 it., the number of axial locations required is ll. From Equation 3 the axial locations are calculated, and from Equation 2, the blade angles are determined. These are as follows:

It may be seen from the foregoing, and under the conditions assumed, that eleven axial locations for the blades or vanes Sti are provided, and that the irst axial location or group of blades is spaced forty-one inches from the middle or vertical centerline of the mold cylinder llS. rlhe first group of vanes are disposed at an angle of approximately 10.2 as measured from a plane extending perpendicular to the mold axis. The blade angle progressively increases moving toward opposite ends of the mold. lt may further be seen that an illustrative blade area is 0.45 square feet, and when twelve openings 31 between the spokes are provided as previously noted, each opening las an area of approximately 9.71 square feet. A range of angles of attack for the blades of from LO to 15 was set forth hereinabove, and at present a preferred angle of attack is 8 and the maximum 15, since at this maximum the angle of attack appears to exceed the stall point and the pumping action becomes somewhat inefficient.

lt was noted hereinabove that the blade angle varies from approximately 10 to 15 from the iirst to the eleventh axial location under the exemplary condition noted. The blade angle is measured from a plane perpendicular to the mold axis, and this is somewhat diagrammatically shown in FIGURE 5. The mold axis is therein designated by the reference line a-b, the blade line is designated by the reference line c-d, and a plane perpendicular to the mold axis has applied thereto in FIGURE 5 the reference legends x-y. [is appears therein, the blade angle is measured from the plane x-y to the blade line c-d, of the blade Sil, and illustratively the blade angle is 14.

The angle of attack, on the other hand, for each blade varies with the velocity of the water in axial flow direction. lt'leasurements of the angle of attack is diagrammatically portrayed in FIGURE 6. The mold axis is therein designated by the reference line cz-b, the blade line of the blade Sil is designated by the reference line c-d, and a plane perpendicular to the mold axis has applied thereto the reference legends x-y. The blade velocity relative to the water in the mold and parallel to the mold axis a-b is represented by a vector quantity e. T he blade velocity relative to the water in the mold and perpendicular to the mold axis is represented by a vector s quantity f. The resultant blade velocity relative to the water in the mold is represented by a vector quantity g. The vector g is the resultant of vectors e and f. The angle of attack a is measured from the blade line c-d of the blade tl to an imaginary extension of the vector quantity g.

By provision of the vanes 8@ constructed and arranged as disclosed, white water flowing from the vat into the mold cylinder 115 is pumped axially in opposite directions toward the open ends of the mold cylinder. ln the arrangement illustrated, the mold cylinders 15 and M5 rotate in a counter-clockwise direction as viewed in FIG- URE 2, and fluid is impelled by the hat blade surfaces axially without introducing a degree of turbulence which would interfere with proper web formation. By tipping and canting the blades 1S and S@ as illustrated, a suflicient velocity is imparted to the White water to accomplish a ow rate uniform throughout the axial length of the mold cylinder. In this manner, drainage of white water through the foraminous covering 16 or 116 and into the mold interior is also uniform, and there is eliminated the prior art problem of relatively heavier web buildup adjacent opposite ends of the mold. The vanes or blades or paddles of course urge the white water through the openings 81 in FIGURES 3 and 4 between the spokes 75 on the spider or sleeve 119, and by disposing the vanes 863 in general axial alignment with these openings, a smooth. luid low is provided and the moving iiuid streams are not cast or iung against the spokes 75 to introduce unduly turbulent conditions.

It has been noted hereinabove that other vat arrangements can be utilized in the practice of this invention, and

the arrangement of FIGURES 1 and 2, the number of axial locations for the blades, blade angles and the other variables can readily be calculated following the procedure set forth above for the structure FIGURES 3 and 4. It is accordingly believed quite apparent that this invention is susceptible to numerous changes and modiiications without departing from the novel concepts thereof.

While FlGURES l and 3 show the blades extending outwardly at an angle to a line perpendicular to the axis of the mold, it will be understood that this is for purposes of illustration only and that the blades in many constructions will extend perpendicularly outwardly from the mold axis.

We claim as our invention:

l.. In a cylinder mold machine having a rotatable forming cylinder receiving white Water therein, the improvement of axially spaced propeller-type blades in the cylinder extending radially from the axis of the cylinder for inducing water flow to both ends of the cylinder, each of said blades having an angle such that the blade angles of the blades at the ends of the cylinder are greater and the blade angles of the blades situated axially inwardly toward the center of the cylinder are progressively less so as to maintain a uniform water level in the cylinder and thereby effect uniform paper formation across the width of the machine.

2. In a cylinder mold machine having a rotatable forming cylinder receiving white water therein, a central supporting member, and axially spaced propeller-type blades connected to said supporting member and providing the internal support for said cylinder, each of said blades having an angle such that the blade angles of the blades at the ends of the cylinder are greater and the blade angles of the blades situated axially inwardly toward the center of the cylinder are progressively less, said blades inducing water tlow to both ends of the cylinder to maintain a uniform water level in the cylinder and thereby effect uniform paper formation across the Width of the machine.

3. In a cylinder mold machine having a rotatable forming cylinder receiving white water therein, a central supporting member, and axially spaced propeller-type blades connected to said supporting member and extending radially outwardly therefrom, each of said blades having an angle such that the blade angles of the blades at the ends of the cylinder are greater and the blade angles of the blades situated axially inwardly the center of the cylinder are progressively less, for inducing water flow to both ends of the cylinder to maintain a uniform water level in the cylinder and thereby effect uniform paper formation across the width of the machine.

4. ln a cylinder mold machine, a vat, shaft means journaled for rotation at opposite ends of said vat, a plurality of radially extending axially spaced propellertype blades connected to said shaft means, and a foraminous covering supported radially outwardly of said blades and dening a forming cylinder receiving white water therein, each of said blades having an angle such that the blade `angles of the blades at the ends of the cylinder are greater and the blade angles of the blades situated axially inwardly toward the center of the cylinder are progressively less for inducing water ow to both ends of the cylinder and outwardly from opposite ends of said vat to maintain a uniform water level in the cylinder and thereby effect uniform paper formation across the width of the machine. c

5. In a cylinder mold machine, a vat, shaft means journaled for rotation at opposite ends of said vat, a plurality of radially extending axially spaced propeller-type blades connected to said shaft means, rim means connected to the outer ends of said blades, and a foraminous covering supported on said rim means and defining a forming cylinder receiving white water therein, each of said blades having an angle such that the blade angles of the blades at the ends of the cylinder are greater and the blade angles of the blades situated axially inwardly toward the center of the cylinder are progressively less for inducing water ow to both ends of the cylinder and outwardly from opposite ends of said vat to maintain a uniform water level in the cylinder and thereby effect uniform paper formation across the width of the machine.

6. In a cylinder mold machine, a vat, shaft means journaled for rotation at opposite ends of said vat, a plurality of axially spaced and radially extending spoke members connected to said shaft means and being circumferentially spaced thereon to provide axial iiuid ow paths, a l

foraminous covering supported by said spoke members and defining a forming cylinder receiving white Water therein, and a plurality of radially extending axially spaced propeller-type blades located in the axial spaces between the spoke members for pumping water along the axial ilow paths between said spoke members and toward opposite ends of the cylinder to maintain a uniform water level in the cylinder and thereby effect uniform paper formation across the width of the machine, each of said blades having an angle such that the blade angles of the blades at the ends of the cylinder are greater and the blade angles of the blade situated axially inwardly toward the center of the cylinder are progressively less.

'7. In a cylinder mold machine having a forming cylinder receiving white water therein,

a shaft rotatably supporting said cylinder, and axially spaced and radially outwardly extending propellertype vanes mounted on said shaft for rotation with said cylinder for inducing water to both ends of the cylinder,

the axial spacing between vanes decreasing progressively from the middle vertical centerline of the cylinder toward opposite ends thereof in order to maintain a uniform water level in the cylinder and thereby effect uniform paper formation thereacross.

8. In a cylinder mold machine having a forming cylinder receiving white water therein,

a shaft rotatably supporting said cylinder, and axially spaced and radially outwardly extending propellertype vanes mounted on said shaft for rotation with said cylinder for inducing water to both ends of the cylinder,

each of said vanes being mounted on said shaft at a constant angle to a plane perpendicular to the axis of said shaft, and

said vane angle of the vanes increasing progressively from the middle vertical centerline of the cylinderV toward opposite ends thereof in order to maintain a uniform water level in the cylinder and thereby effect uniform paper formation thereacross.

9. In a cylinder mold machine having a forming cylinder receiving white water therein,

a shaft rotatably supporting said cylinder at the axis of said cylinder, and

propeller-type vanes mounted on the shaft and rotatable with the cylinder,

said vanes being mounted at an angle to a plane passing through the vane perpendicularly to said axis, and having an angle of attack said Varies being spaced along the axis symmetrically on each side of the center of the cylinder in N series, each series being a distance x from the center of the cylinder wherein a is from 1 to 15 and ,8,

x and N are defined approximately by the equations:

N being the number of axial locations of blades hT being the total head drop from center to edge of mold in feet n being the number of blades per axial location flv being the single blade area-span l, x chord, c, in square feet being the angle of attack in degrees x being the axial distance from middle of mold in inches being the blade angle in degrees (measured from a plane perpendicular to the mold axis).

References Cited bythe Examiner UNITED STATES PATENTS 581,732 5/97 Keeney 162-335 811,660 2/26 Parker 162-357 2,669,910 2/54 Trotman 162-357 3,007,576 11/61 Hannaford 209-288 FOREIGN PATDNTS 296,228 1/ 17 Germany.

DONALL H. SYLVESTER, Primary Examiner.

RICHARD D. NEVIUS, Examiner. 

1. IN A CYLINDER MOLD MACHINE HAVING A ROTATABLE FORMING CYLINDER RECEIVING WHITE WATER THEREIN, THE IMPROVEMENT OF ACIALLY SPACED PROPELLAR-TYPE BLADES IN THE CYLINDER EXTENDING RADIALLY FROM THE ACIS OF THE CYLINDER FOR INDUCING WATER FLOW TO BOTH ENDS OF THE CYLINDER, EACH OF SAID BLADES HAVING AN ANGLE SUCH THAT THE BLADE ANGLES OF THE BLADES HAVING AN ANGLE SUCH THAT THE BLADE ANGLES OF THE BLADES AT THE ENDS OF THE CYLINDER ARE GREATER AND THE BLADE ANGLES OF THE BLADES SITUATED AXIALLY INWARDLY TOWARD THE CENTER OF THE CYLINDER ARE PROGRESSIVELY LESS SO AS TO MAINTAIN A UNIFORMM WATER LEVEL IN THE CYLINDER AND THEREBY EFFECT UNIFORM PAPER FORMATION ACROSS THE WIDTH OF THE MACHINE. 